/Engine/Source/Runtime/Experimental/GeometryCollectionEngine/Public/GeometryCollection/GeometryCollectionEngineConversion.h
Get a HiRes (or LOD 0 if no HiRes available) MeshDescription for the given static mesh, and make sure it includes normals and tangents. (i.e., to pass to AppendMeshDescription)
static [FMeshDescription](API\Runtime\MeshDescription\FMeshDescription) * GetMaxResMeshDescriptionWithNormalsAndTangents ( const [UStaticMesh](API\Runtime\Engine\Engine\UStaticMesh) * StaticMesh )